Singapore Air Lines was the first
carrier to introduce the "Big Top"
747-300
present Efis (electronic flight instrument
system), and intends to concentrate its
thinking on the expansion of the system
and its interrogation for engineering
troubleshooting from the cockpit, a philo
sophy already seen in the 737-300. Boeing
insists that the role of the crew is navigat
ing the aircraft, and will design out any
in-flight investigatory role. This will con
tinue to influence the range of parameters
displayed—or available for display—to the
crew, and will doubtless consolidate the
question of crew composition.
Boeing regards the control data unit
(CDU) layout for the Sperry flight
management system (FMS) in the
757/767 as a sound and proven
keyboard/controller for pilot access and
operation, and the system's functioning
and architecture well matched to naviga
tion and performance management tasks.
For this reason a very similar layout and
function was chosen for the Lear-Siegler
fit to the 737-300—accepting the slightly
different interface requirements with the
older aircraft design.
The professed Boeing aim in systems is
functional simplicity, redundancy, and
automatic backup or change-over—
furthering the aim of minimum need for
crew diagnosis. Without a need for diagno
sis there is, in their view, no need for
extending the EICAS concept to include
active systems' state schematics or
"synoptics" in Airbus style.
The electronic display of engine para
meters is seen as a successful innovation
which was not followed elsewhere simply
because of a lack of readiness among other
manufacturers. Boeing is not ready yet to
accept a side-by-side layout for attitude
and horizontal situation displays as
planned for the A320. It is thought more
acceptable if larger CRT displays or other
types of display screen are needed, and
this is to be looked at in conjunction with
wider developments in flightdeck data
usage.
Head-up displays (HUD) have become
more practical with the fit of lower-error
attitude reference systems. But the
emphasis remains on Cat III autopilots
which incorporate high redundancy, are
self monitoring, and do not justify the
addition of HUD. HUD is more attractive
for retrofitting to aircraft which are suit
able for a refit of high-accuracy attitude/
heading reference systems, and this is
being given attention.
Centralised avionics management has
been under study for some time, and its
application has been researched on a 727.
Again Boeing seems wary of over-
zealous use of digital technology. It
accepts that operators like the power and
user-flexibility of such systems but baulk
at the degree of verification and,
importantly, required recertification of
programmes and hardware after the
merest change of a "bit". It is important
for purchasers to bear in mind the poten
tial for running costs in their own initial
costings and consequent choice of fit.
Voice recognition and control is part of
an overall long-term corporate laboratory
programme which embraces the wider
fields of workload study and—in the very
long term—artificial intelligence. It is
agreed that voice selection of NAV/COM
channels and of Efis display format and
parameters is well within the state of the
art, and compatible with the manner of
function of such equipment. But any
application to the civil field is regarded as
premature—stressing, once again, the
conflict between industry capability and
the civil operators' needs.
Present corporate research is inevitably
directed at the military; the need is clear
in the single-pilot cockpit, where rapid
response to a succession of critical and
complex inputs may be prejudiced if the
manual selection of functions and para
meters continues to be necessary.
Fly-by-wire (FBW) is not being looked
at alone, but in parallel with fly-by-light.
Thinking is directed at abandoning the
traditional fly-by-rod-and-cable. The
weight-saving aspects are important, but
FBW does not supply a complete answer
when it demands considerable shielding
from electro-magnetic interference. The
main aim is control precision, freed from
the problems of slack and adjustment that
go with mechanical links in systems, for
flight control and engine control.
There is no novelty in principle;
Concorde uses FBW technology for input
to its hydraulic power controls, albeit with
manual backup, and it is an established
feature of military aircraft. Completely
electric/electronic control is currently a
feature of FADEC (full authority digital
engine control) in the newly certificated
PW2037.
The future application of "Fly-by-X" in
any role is a matter of time in new aircraft.
Boeing's timing of any future applications
is coloured by the prospect of carrying a
parallel burden of the "learning" by certi
fication authorities that necessarily goes
with new technology and new applica
tions—and here it seems to be hinting at
recent experience.
When it comes to sidesticks Or side-
arm-controllers it is argued that this is a
separate issue to that of FBW. Boeing
prefers to look at the ergonomic and
physiological aspects of the former, while
letting their "FBX" thinking run in paral
lel. The two concepts would be brought
together later, if it was seen that there was
a particularly suitable application. Boeing
is very wary of prejudicing either one or
the other in any premature tandem devel
opment project. Results from earlier
research experience with the "parallel
sticks" control in a 737 were not satis
factory. Basically the idea of minia
turisation on conventional lines has
seemed more attractive than going for
complete novelty—Boeing has what it
calls "other concepts" in mind, but was
not willing to be drawn on these.
Finally, nowhere is the conservative and
superficially reserved approach of
Boeing's massive experience more evident
than in the field of the future application
of active controls, artificial stability, and
e.g. control. Thinking may be well
advanced; but the stated views are that
these are general tools within the estab
lished state of the art, and that it would be
a mistake to see them automatically as a
substitute for structure, design detail, or
well-proven simpler design practices.
Studies in these areas, as in all others, are
subjected to the primary Boeing test in
design: cost benefit analysis. •
30 FLIGHT International, 19 January 1985